Factor VIII is a protein found in blood plasma which acts as a cofactor in the cascade of reactions leading to blood coagulation. A deficiency in the amount of Factor VIII activity in the blood results in the clotting disorder known as hemophilia A, an inherited condition primarily affecting males. Hemophilia A is currently treated with therapeutic preparations of Factor VIII derived from human plasma or manufactured using recombinant DNA technology. Such preparations are administered either in response to a bleeding episode (on-demand therapy) or at frequent, regular intervals to prevent uncontrolled bleeding (prophylaxis).
Factor VIII is known to be relatively unstable in therapeutic preparations. In blood plasma, Factor VIII is usually complexed with another plasma protein, von Willebrand factor (vWF), which is present in plasma in a large molar excess to Factor VIII and is believed to protect Factor VIII from premature degradation. Another circulating plasma protein, albumin, may also play a role in stabilizing Factor VIII in vivo. Currently marketed Factor VIII preparations therefore primarily rely on the use of albumin and/or vWF to stabilize Factor VIII during the manufacturing process and during storage.
The albumin and vWF used in currently marketed Factor VIII preparations is derived from human blood plasma, however, and the use of such material has certain drawbacks. Because a large molar excess of albumin compared to Factor VIII is generally added in order to increase the stability of the Factor VIII in such preparations, it is difficult to characterize the Factor VIII protein itself in these preparations. The addition of human-derived albumin to Factor VIII is also perceived as being a disadvantage with respect to recombinantly-produced Factor VIII preparations. This is because recombinantly-derived Factor VIII preparations, in the absence of such added albumin, would otherwise contain no human-derived proteins, and the theoretical risk of transmitting a virus would be reduced.
Several attempts to formulate Factor VIII without albumin or vWF (or with relatively low levels of these excipients) have been described. For example, U.S. Pat. No. 5,565,427 (EP 508 194) to Freudenberg (assigned to Behringwerke) describes Factor VIII preparations which contain particular combinations of detergent and amino acids, specifically arginine and glycine, in addition to excipients such as sodium chloride and sucrose. The detergent, polysorbate 20 or polysorbate 80, is described as being present in amounts of between 0.001 to 0.5% (v/v), while arginine and glycine are present in amounts of between 0.01 to 1 mol/l. Sucrose is described as being present in amounts of between 0.1 and 10%. Example 2 of this patent asserts that solutions of (1) 0.75% sucrose, 0.4 M glycine, and 0.15M NaCl, and (2) 0.01 M sodium citrate, 0.08 M glycine, 0.016M lysine, 0.0025 M calcium chloride, and 0.4 M sodium chloride were not stable in solution over 16 hours, whereas solutions of (3) 1% sucrose, 0.14 M arginine, 0.1 M sodium chloride and (4) 1% sucrose, 0.4 M glycine, 0.14 M arginine, 0.1 M sodium chloride, and 0.05% TWEEN® 80 (polysorbate 80) exhibited stability.
U.S. Pat. No. 5,763,401 (EP 818 204) to Nayer (assigned to Bayer) also describes a therapeutic Factor VIII formulation without albumin, comprising 15–60 mM sucrose, up to 50 mM NaCl, up to 5 mM calcium chloride, 65–400 mM glycine, and up to 50 mM histidine. The following specific formulations were identified as being stable: (1) 150 mM NaCl, 2.5 mM calcium chloride, and 165 mM mannitol; and (2) 1% sucrose, 30 mM sodium chloride, 2.5 mM calcium chloride, 20 mM histidine, and 290 mM glycine. A formulation containing higher amounts of sugar (10% maltose, 50 mM NaCl, 2.5 mM calcium chloride, and 5 mM histidine) was found to exhibit poor stability in the lyophilized state compared with formulation (2).
U.S. Pat. No. 5,733,873 (EP 627 924) to Osterberg (assigned to Pharmacia & Upjohn) discloses formulations which include between 0.01–1 mg/ml of a surfactant. This patent discloses formulations having the following ranges of excipients: polysorbate 20 or 80 in an amount of at least 0.01 mg/ml, preferably 0.02–1.0 mg/ml; at least 0.1 M NaCl; at least 0.5 mM calcium salt; and at least 1 mM histidine. More particularly, the following specific formulations are disclosed: (1) 14.7–50–65 mM histidine, 0.31–0.6 M NaCl, 4 mM calcium chloride, 0.001–0.02–0.025% polysorbate 80, with or without 0.1% PEG 4000 or 19.9 mM sucrose; and (2) 20 mg/ml mannitol, 2.67 mg/ml histidine, 18 mg/ml NaCl, 3.7 mM calcium chloride, and 0.23 mg/ml polysorbate 80.
Other attempts to use low or high concentrations of sodium chloride have also been described. U.S. Pat. No. 4,877,608 (EP 315 968) to Lee (assigned to Rhone-Poulenc Rorer) teaches formulations with relatively low concentrations of sodium chloride, namely formulations comprising 0.5 mM–15 mM NaCl, 5 mM calcium chloride, 0.2 mM–5 mM histidine, 0.01–10 mM lysine hydrochloride and up to 10% sugar. The “sugar” can be up to 10% maltose, 10% sucrose, or 5% mannitol.
U.S. Pat. No. 5,605,884 (EP 0 314 095) to Lee (assigned to Rhone-Poulenc Rorer) teaches the use of formulations with relatively high concentrations of sodium chloride. These formulations include 0.35 M–1.2 M NaCl, 1.5–40 mM calcium chloride, 1 mM–50 mM histidine, and up to 10% of a “sugar” such as mannitol, sucrose, or maltose. A formulation comprising 0.45 M NaCl, 2.3 mM calcium chloride, and 1.4 mM histidine is exemplified.
International Patent Application WO 96/22107 to Roser (assigned to Quadrant Holdings Cambridge Limited) describes formulations which include the sugar trehalose. These formulations comprise: (1) 0.1 M NaCl, 15 mM calcium chloride, 15 mM histidine, and 1.27 M (48%) trehalose; or (2) 0.011% calcium chloride, 0.12% histidine, 0.002% Tris, 0.002% TWEEN® 80, 0.004% PEG 3350, 7.5% trehalose, and either 0.13% or 1.03% NaCl.
Other therapeutic Factor VIII formulations of the prior art generally include albumin and/or vWF for the purpose of stabilizing Factor VIII and are therefore not relevant to the present invention. For example, U.S. Pat. No. 5,328,694 (EP 511 234) to Schwinn (assigned to Octapharma AG) describes a formulation which includes 100–650 mM disaccharide and 100 mM–1.0 M amino acid. Specifically, the following formulations are disclosed: (1) 0.9 M sucrose, 0.25 M glycine, 0.25 M lysine, and 3 mM calcium chloride; and (2) 0.7 M sucrose, 0.5 M glycine, and 5 mM calcium chloride.
While several attempts have been made to formulate Factor VIII without albumin or vWF, there remains a need for therapeutic Factor VIII formulations which are stable in the absence of albumin or other proteins.